While time may adorn you with new lines on your face, a new color hair (gray) and a new waistline, the passing decades are not to blame for all of the changes in your body. Your eating habits, your attitude and your approach to everyday experiences also play key roles.

As we age, our bodies lose muscle and gain fat. Our nutritional needs change, as well. But you don’t necessarily feel these changes on a daily basis. Metabolism gradually slows each decade after age 20, so it's not as if you suddenly wake up 10 pounds heavier. It creeps up slowly. Fortunately, you do have some control over your changing body and slowing metabolism. Some strategies to help you avoid a midlife diet crisis:

Shave your portion sizesThe average woman needs about 100 fewer daily calories at age 40 than at 20.

While there’s no need to give up your favorite foods, it’s easier to keep calories in check by using "snack-pack" sizes as a guide. To avoid weight gain it’s important that you eat enough high-quality protein such as lean meat, poultry and fish, but not too much. For women over age 25, the recommended allowance for protein is 50 grams a day. A piece of chicken the size of a deck of cards is 21 grams of protein. A cup of skim milk has around 8 grams and 1/3 cup of beans is 5 grams.

Give your brain a boost
If you’re forgetting things more than ever, it doesn’t necessarily mean that your brain is deteriorating. You may be overtired or dealing with an overloaded schedule. As you try to lighten your calorie intake, don't skip meals, however. Keep your brain sharp by consuming by consuming a bouquet of antioxidant-rich fruits and vegetables. Choose deeply colored produce such as sweet potatoes, strawberries and blueberries, as well as, dark green leafy vegetables such as kale.

There are powerful antioxidants in some white foods, too, such as cauliflower, onions and garlic. The bottom line is: Eat more fruits and vegetables for your brain and body.

Do a balancing actA recent published study from Columbia University Medical Center found that increased levels of blood sugar were correlated to decreased mental sharpness. Keep your blood sugar balanced by combining: almond butter with whole grain crackers; low-fat or part-skim cheese and whole grain bread; hummus and fresh veggies; or whole grain cereal and skim milk. A container of low-fat, low-sugar yogurt is a good protein-carb combination. These combos will also curb your appetite and help with weight loss.

Make a deposit in the bone bank
At least 28 million older Americans have osteoporosis and low bone mass. If you haven’t had your Vitamin D level checked, be sure to ask your physician to take this simple blood test at your next exam.

The dynamic duo of vitamin D and calcium helps to strengthen your bones to prevent this crippling disease, so be sure to get 1,500 mg of calcium and 400 IU of vitamin D, preferably from food sources such as skim milk and yogurt or a combination of supplements.

The best bone-boosting foods are low-or non-fat dairy products. There's also calcium in canned salmon with bones, broccoli and fortified soy milk and orange juice. Try to choose products that have a high daily value (20 percent) for calcium. You can find calcium values on the nutrition facts panel.

Rates of women who are opting for preventive mastectomies, such as Angeline Jolie, have increased by an estimated 50 percent in recent years, experts say. But many doctors are puzzled because the operation doesn't carry a 100 percent guarantee, it's major surgery -- and women have other options, from a once-a-day pill to careful monitoring.

Drink from the fountain of youth
One of the simplest things you can do for your body is to drink plenty of water. Water will moisturize your skin and help it stay clear, smooth and younger looking, while also flushing out the body’s toxins.

Decaffeinated green tea is soothing and high in antioxidants which help boost metabolism. Caffeinated beverages stimulate your metabolic system, but can have a dehydrating effect on your skin.

Have a birthday party
“Life begins at 40,” my mother said as she entered her fourthdecade. I was only 8-years-old at that time, but I remember exactly how I felt: “Wow, she’s old.”

Now, as I’m about to turn 54, I naturally hold a completely different opinion when it comes to the inevitable process of aging. Although the years are increasing, they’re just numbers. If you are able to stay healthy, physically and emotionally, you’ll have good reason to celebrate, no matter how many candles you have to blow out.

Bonnie Taub-Dix, R.D., is a spokesperson for the American Dietetic Association and weight control expert in New York City.